Air conditioning refrigeration system



Jun 12, 1951 w. A. MINKLER ETAL AIR CONDITIONING REFRIGERATION SYSTEMFiled May 29, 1948 All' INVENTORS wlLLlAM A. M|NKLER+ ELDON H. LUSKATTORNEY Patented June 12,. 1951 5seen Uhll'l'ED STATES RATEN' OFFlCEAIR CONDITIONING REFRIGERATION SYSTEM William A. Minklcr, Elmhurst,Ill., and Eldon H.

Lusk, East Paterson, N. J., assignors to Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of iennsylvaniaApplication May 29, 1948, Serial No. 29,974

9 Claims.

This invention relates to refrigeration systems,

land relates more particularly to air-conditioning cause excessive wearof the compressors and of the motors driving same.

This invention overcomes the disadvantages of the prior systems bymaintaining a refrigerant compressor in constant operation down to azero load condition; by partially unloading the compressor upon a fallin load below capacity load; and then upon a further fall in load, usingheat from a condenser of the system for heating a cooling fluid suppliedtothe air cooler.

In one embodiment of the invention, an indirect air-cooling system has awater Chiller which supplies chilled water to the air cooler. Thecompressor is operated continuously and, upon a predetermined reductionin load in the conditioned space, the compressor is unloaded to 50% ofits capacity. Upon a further reduction in the load in the conditionedspace, a portion of the water from the water chiller is heated in anauxiliary condenser whereby the temperature of the chilled watersupplied to the air cooler is raised sufficiently to compensate for thereduction in load vbelow the 50% level. Thus, the temperature `and thehumidity in the conditioned space are maintained constant by thecontinuous operation of the compressor, and the wear resulting from thestarting and stopping of the compressor is L uniform conditions in anair-cooled space by operating a refrigerant compressor used for coolingthe air, continuously.

The invention will now be described with reference to the drawing whichis a diagrammatic View of an air-conditioning system using an indirectreirigeration system for cooling the air.

The air cooler I0, which may be a conventional vair washer or inned-tubecooler, is connected to a conventional fan I I which moves the air to becooled through the cooler IU and discharges itv into the conditionedspace.

The pump I2 circulates water through the air cooler I il, the heatexchanger I3 in the water chiller I4, and the three-way Valve I5.

The compressor i6, driven by the electric motor i'l, supp-liesrefrigerant vapor through the auxiliary condenser i8, the main condenserI9, and the expansion valve 20, into the water Chiller I4 around theheat exchanger I3, the refrigerant being returned through the pipe 2| tothe suction side of the compressor.

The compressor has the unlcader 22 which is actuated by the solenoid 24to unload the compressor to 50% capacity when the solenoid is energized.Y

The solenoid 24 has two energizing windings'` 4I and` 42, the winding 4Ibeing connected to energize the solenoid under control of the thermostat23, the winding 42 being connected to energize the solenoid when thesystem is rst started up, as will be described.

The thermostat 23 is of the bellows type and has the plunger 25 carryingat its lower end the contacts 26 and 2'I which are electricallyseparated by the insulator 28. The contact 21 is connected in serieswith the energizing winding of the relay 29, the solenoid 30, whichadjusts the valve l5, a power supply source, which is not illustrated,and the resistor 3| when the contact 2l is in contact with the resistor.Y

The contacts of the relay 29 are connected in series with the powersupply source, and the energizing winding lll of the solenoid 24, whenthe contact 2`l'touches the resistor 3l.

The winding 42 of the solenoid 24 is connected in series with the powersupply source, the armature 38 and the contact 39 of the switch 35 whenthe switch is closed to start the compressor.

The contact strip 32, the contact 26, the power supply source, thecompressor motor I'I, the timer 49, and the contact 3l, and the armature36 of the starter switch 35, are connected in series when the starterswitch is closed.

The armature 38 of the switch 35, touches its contact 39 when the switchis closed, and is moved by the timer 40 away from its contact 39 apredetermined time interval after the switch is closed, for energizingthe solenoid winding 42 so that the unloader 22 will unload thecompressor, unless the solenoid winding 4I is energized at that time bythe thermostat 23.

To start the system, the starter switch 35 would be closed causing,through the contact of the armature 36 with the contact 31, the motor I1to start the compressor, and causing, through the contact of thearmature 38 with the contact 39, the solenoid winding 42 to be energizedso it actuates the unloader 22 for unloading the compressor. By startingthe compressor partially unloaded, the power required for startingV isreduced, and wear on the compressor and-its driving motor is reduced.

After a predetermined time interval which may, by way of example, be twominutes, the timer 40 would move the armature 38 away from the contact33 so as to deenergize the solenoid winding 42. The solenoid 24 wouldthen adjust the unloader 22 to load the compressor 100%, unless at thattime the thermostat 23 will have caused the solenoid winding 4I to beenergized.

Ordinarily, when the system is iirst started up, the thermostat 23 willnot have moved the contact 21 against the resistor 3l, so that after thetimer 40 has acted to cause the compressor to be 100% loaded, thecompressor will continue to operate at full capacity until the load inthe conditioned space has been substantially reduced, at which time thebellows of the thermostat will contract sufficiently to move the contact31 against the resistor 3|.

This would cause the relay 29 to be energized so that it would close thecircuit from the power supply to the winding 4I of the solenoid 2 of theunloader 22, causing the solenoid to be energizedv and to unload thecompressor to 50% capacity.

At the saine time, the solenoid 3E would be energized causing it toadjust the valve I5 so that a portion of the chilled water from thewater chiller I4 would be circulated through the condenser' I8, thecondenser heating the water sufli'ciently4V to make up for the reductionin the load in the conditioned space.

By way of example, the thermostat may move the contact 21 against theresistor 3| when the temperature in the conditioned space fallsbelow'76" F.

As the load in the conditioned space continues to decrease, the bellows24 would expand further so as'v to move the contact 21 further along theresistor 3l so as to reduce the value of the electric resistance in thecircuit of the solenoid 30, causing the solenoid to become more stronglyenergized so as to adjust the valve I5 to permit more chilled water tocirculate through the condenser IB. Thus, every reduction in load belowthe rst reduction is compensated for by an increase in the amount ofheat added to the air chilling water, so that the conditions in theconditioned space are maintained uniform, and the compressor ismaintained continuously in operation.

When the temperature in the conditioned space rises, say to '17 F., sothat the load in the conditioned space is such that the compressor wouldbe called upon to operate at full capacity, the thermostat 23 will havemovedA the contact 21 away from the resistor 3I, sc that the valve I5would be so adjusted that no chilled water would be circulated throughthe condenser E3.

During the contraction of the thermostat bel- `lows caused by loadreductions, the contact 25 will slide along the strip 32 causing thecompressor to remain continuously in operation throughout the entireload range. At zero load, when there would be no need for cooling, the

4 I contact 23 would move below the strip 32, thus opening the circuitof the motor I1 and stopping the compressor.

While one embodiment of the invention has been described for the purposeof illustration, it should be understood that the invention is notlimited to the exact apparatus and the arrangement of apparatusillustrated, as modifications thereof may be suggested by those skilledin the art withoutdeparture from the essence of the invention.

What is claimed is:

l. A refrigeration system comprising a refrigerant compressor, acondenser, and a water chiller connected in a refrigerant circuit; acooler; means including a valve connecting said water' chiller and saidcooler in a water circuit when said valve is adjusted to one position,and connecting said water chiller, said condenser, and said cooler in awater circuit when said valve is adjusted to a second position; andmeans responsive to a reduction in the load on said cooler for adjustingsaid valve to said second position.

2. A refrigeration system comprising a refrigerant compressor, acondenser, and a water chiller connected in a refrigerant circuit; acooler; means including a valve connecting said water chiller and saidcooler in a water circuit when said valve is adjusted toone position,and connecting' said water chiller, said condenser, and said cooler in awater circuit when said valve is adjusted to a second position; anunloader for said compressor; and means responsive to a reduction intheload on said cooler' for adjusting said valve to said second position,and for actuating said unloader `for partially unloading said?compressor.

3. A refrigeration systeml comprising a refrigerant compressor, a maincondenser, an auxiliary condenser, and a water chiller connected in arefrigerant circuit; a cooler connected to said water chiller forreceiving water therefrom; an unloader for said compressor; and meansresponsive to a reduction in the load on said cooler for actuating saidunloader for partially unloading said compressor, and for routing thechilled water from said chiller in heat exchange relationship with saidauxiliary condenser.

4. A refrigeration system comprising a refrigerant compressor, a maincondenser, an auxiliary condenser, and a water chiller connected in arefrigerant circuit; a cooler; means including a valve connecting saidwater chiller and said cooler in a water circuit when said valve isadjusted' to one'position, and connecting said water chiller, saidauxiliary condenser, and said cooler in a water circuit when said valveis adjusted to a second position and means responsive to a rcduotion inthe load on said cooler for adjusting said valve to said secondposition.

5. A refrigeration system comprising a refrigerant compressor, a maincondenser, auxiliary condenser, and a water chiller connected in arefrigerant circuit; a cooler; means including a valve connecting saidwater chiller and said, cooler in a water circuit when said valve isadjusted to one position, and connecting said water chiller, saidauxiliary condenser, and said cooler in a Water circuit when said valveis adjusted to a second position; an unloader for said compressor; andmeans responsive to a reduction in the load on said cooler for adjustingsaid valve to said second position, and for actuating said unloader forpartially unloading said compressor.

assassa 6. A refrigeration system comprising a refrig-A erantcompressor, a condenser, and a Water chiller connected in a refrigerantcircuit; a cooler; means including a valve connecting said water chillerand said cooler in a Water circuit When said valve is adjusted to oneposition, and connecting said water chiller, said condenser, and saidcooler in a water circuit when said valve is adjusted to a secondposition; means responsive to a reduction in the load on said cooler foradjustingsaid valve to said second position, and means responsive tofurther reductions in the load on said cooler for adjusting said valvefor varying the volume of water circulated through said condenserconformably with the reduction in load.

7. A refrigeration system comprising a refrigerant compressor, acondenser, and a water chiller -connected in a refrigerant circuit; acooler;

means including a valve connecting said water chiller and said cooler ina Water circuit when said valve is adjusted to one position,andconnecting said water chiller, said condenser, and said cooler in awater circuit when said valve is adjusted to a second position; anunloader for said compressor; means responsive to a reduction in theload in the space served by said cooler for actuating said unloader forpartially unloading said compressor and for adjusting said valve to saidsecond position, and means responsive to further reductions in said loadfor adjusting said valve for varying the volume of Water circulatedthrough said condenser condenser conformably with the reduction in load.

8. A refrigeration system comprising a refrigerant compressor, a maincondenser, an auxiliary condenser, and a Water chiller connected in arefrigerant circuit; a cooler; means including a valve connecting saidWater chiller and said cooler in a water circuit when said valve isadjusted to one position, and connecting said Water chiller, saidauxiliary condenser, and said cooler in a water circuit when said valveis adjusted to a second position; and means responsive to a reduction inthe load on said cooler for adjusting said valve to said secondposition, and means responsive to further reductions in said load foradjusting said Valve for varying the volume of water circulated throughsaid condenser conformably with the reduction in load.

9. A refrigeration system comprising a refrigerant compressor, a maincondenser, an auxiliary condenser, and a water chiller connected in arefrigerant circuit; a cooler; means including a valve connecting saidWater chiller and said cooler in a Water circuit when said valve isadjusted to one position, and connecting said water Chiller, saidauxiliary condenser, and said cooler in a Water circuit When said valveis adjusted to a second position; an unloader for said compressor; andmeans responsive to a reduction in the load on said cooler for adjustingsaid valve to said second position, and for actuating said unloader forpartially unloading said compressor, and means responsive to furtherreductions in said load for adjusting said valve for varying the volumeof Water circulated through said condenser confprmably with thereduction in load.

WILLIAM A. MINKLER. ELDON H. LUSK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,980,688 Lewis Nov. 13, 19342,152,250 Gay Mar. 28, 1939 2,160,389 Palmer May 30, 1939 2,187,397Goggins Jan. 16, 1940 2,223,725 Heitchue Dec. 3, 1940

